A leader of a protest outside Pakistan’s parliament on August 20 called for his followers to blockade the building as lawmakers began talks on the country’s political crisis with Prime Minister Nawaz Sharif.

Islamist cleric Tahir ul-Qadri told his followers not to allow anyone to enter or leave the legislature.

The parliamentary session comes a day after tens of thousands of demonstrators forced their way into Islamabad’s high-security "red zone" to call for Sharif's resignation.

Opposition politician Imran Khan, leader of a separate protest, told his followers not to storm the parliament building.

But Khan warned he would lead supporters into Sharif’s nearby office if the prime minister does not step down by the evening of August 20.

Police, paramilitary rangers, and army troops were guarding Sharif’s office.

An army spokesman said on Twitter that the “situation requires patience, wisdom, and sagacity from all stakeholders.”